When in trouble, Barack Obama gives big speeches. He has addressed joint sessions of Congress after dismal August recesses, repeatedly interrupted prime-time programming in times of Washington gridlock and pontificated on race when the nation questioned the nature of his Chicago church. Whatever the subject matter of the day, his conceit has been the same. He says he wants to elevate the conversation and then adopts his favored pose: the reasonable adult leader in an era short on reason, adults and leadership.

With job growth slowing, Europe teetering and his gaffe “The private sector is doing fine,” the past two weeks rank among the worst of Obama’s political career. So a speech was in order on June 14, when Obama traveled to a community college in Cleveland, in the most crucial of swing states. The words he spoke — somber, substantial and filled with policy proposals — may be remembered as more consequential than even his campaign announcement in May.

He began by dismissing the political gamesmanship, the “twists and turns” that have characterized the presidential campaign over the past two months, making no mention of his own campaign’s driving role. “There will be no shortage of gaffes and controversies that keep both campaigns busy and give the press something to write about,” he said.

But those small things, he said, would not decide the election. “There’s one place where I stand in complete agreement with my opponent. ‘This election is about our economic future.’ ” It was a sly rhetorical move, since Mitt Romney would much rather the election be about the recent past and Obama’s own performance. But this was a big Obama speech. He was here to recast the debate.

Over the next 45 minutes, the President laid out the differences between the two parties’ economic visions as he saw them. “Governor Romney and his allies in Congress believe deeply in the theory that we tried during the last decade,” he said, citing the presidency of George W. Bush. And then Obama began to describe those plans calmly, methodically and without bombast. This is where Obama the politician, facing the real possibility of defeat in November, transformed himself once again into Obama the reasonable adult. “This is not spin. This is not my opinion,” he said.

And in some respects, he was right. The policy proposals Romney has laid out are incomplete and in some ways contradictory. He has proposed, as the President explained, large tax breaks across all income classes. But he has also vowed broad cuts in government spending, most of which he has not identified. And he has promised some tax increases, through eliminations of special deductions, though he has not identified those either. “If you agree with the approach I just described, if you want to give the policies of the last decade another try, then you should vote for Mr. Romney,” Obama said.

By that point, Obama had adopted the persona of an objective analyst, not a fierce combatant in electoral politics. He quoted a recent report by Mark Hopkins, an economic analyst for Moody’s, who pointed out that Romney’s stated policies were not focused on short-term job creation. “On net, all of these policies would do more harm in the short term,” Hopkins said. “If we implemented all of his policies, it would push us deeper into recession and make the recovery slower.”

“Now, I’m looking forward to the press following up and making sure that you know I’m not exaggerating,” Obama joked.

This was all a far cry from the posture the Obama campaign has taken for much of the past two months, when small-ball negative politics — from the campaign’s description of Bain Capital as a “vampire” to its assault on Romney’s record in Massachusetts — dominated the airwaves. Even as Obama spoke, the Romney campaign was still playing the same game, blasting out e-mails to reporters with gotcha quotes Obama had uttered years ago.

At some point, the election will pivot to more serious discussions, and Obama’s speech suggests his campaign sees an advantage in making the pivot sooner rather than later. The Republican primaries pushed Romney further to the right on policy than he might have hoped, and it is not clear that he can find a way in the coming months to flesh out his policy details without spooking the independent voters he will need to win.

For Obama and his aides, any day spent comparing the President’s plans with Romney’s is a day won. The President does not want the campaign to dwell on the past three years or the present fears of malaise. He wants it to be a debate about the different plans of two candidates for the next four years. He is happy to talk policy.

Obama underscored these points hours later in Manhattan, where he spoke at a $40,000-a-plate dinner fundraiser at the home of actress Sarah Jessica Parker. “We’ve got as fundamental a choice this time out than we have had in 30, 40 or 50 years,” he said. “What we are going to have to do is present very clearly to the American people that choice.”

But he added a moment later that the task would not be easy, given the fact that Republicans planned to spend half a billion dollars on ads with a simpler message: Your current struggles are Obama’s fault. “It’s an elegant message,” Obama said. “It happens to be wrong. But it’s crisp. You can fit it on a bumper sticker.”

The President’s message is harder to boil down like that. But then the President has proved himself more able to give big speeches.